As the snow continues to pile up outside, I can't help but think of polar predators. There are animals that live and hunt in the conditions that are keeping me inside today, and one of my favorites is the leopard seal. An apex predator in its Antarctic home, the leopard seal is an enormous pinniped that specializes in hunting penguins and other seals. Getting into the water with one is not something to be done on a whim, but as described by photographer Paul Nicklen, particularly friendly predators can be among the most frightening: